According to the BBC, the investigators travelled to Oradour-sur-Glane to investigate where different SS units were deployed and will hear from witnesses and survivors.

Some 60 soldiers were brought to trial the 1950s. Twenty of them were convicted but all were later released. East Germany refused to extradite the suspects for the original post-war trial of surviving SS men in France.

The German prosecutor said he hopes a new legal process will begin in Germany but with the suspects now 87 and 88 years old time is short, the BBC reported.

German investigators in Oradour-sur-Glane (Photo: AFP)

On 10 June 1944, a detachment of SS troops surrounded the tiny hamlet in the Limousin region. It has been claimed that they were seeking retribution for the abduction of a German officer but some say that resistance members were based in a different, nearby village.

Most of the victims were women and children. Many of them were herded into a local church into which hand grenades were thrown before it was set on fire.

The men were locked in a barn. Machine-gunners shot at their legs, then doused them in petrol and set them alight.

"Lots of the people concerned are now old men like me, who may well have lost their memories. Nonetheless, it is good that Germany is taking responsibility for Oradour and remain concerned by it," survivor Robert Hebras said.

'Today blood must flow'

The Der Spiegel website said that at the heart of the investigation is a junior SS officer who was stationed in France in the summer of 1944. "Today, blood must flow," Heinz Barth reportedly said hours before the massacre.

"As a state prosecutor, one of the things that I must prove is that the perpetrators knew that murders were taking place," Andreas Brendel, head of the central Nazi war crimes investigation unit in Dortmund, told SPIEGEL ONLINE.

"Barth's statement means that members of the unit knew what was going to happen on that day. That was one of the main things that encouraged me to reopen the investigation."

Barth himself was sentenced to life in prison by the East German court. He was released in 1997 due to his poor health and died in 2007.